As medical researchers gradually come to understand the physical and chemical changes that occur in the Alzheimer's brain, they can use their knowledge to develop treatments that effectively prevent or reverse these changes. Many experimental studies using drug therapies on Alzheimer's patients already have been tried, with varying degrees of success. While no “wonder” drug for Alzheimer's disease—or even a clear and consistent treatment approach—has yet emerged, research has shown that some drugs help some of the people some of the time. Unfortunately, the studies completed thus far often show puzzling inconsistencies in response from one patient to the next. To achieve more consistent results, we no doubt need to learn more about the nature of the illness and its causes.
To date, several major groups of drugs have been investigated. Many of the drug interactions in research have attempted to correct the deficiencies in the brain's cholinergic system. Since the neurotransmitter acetylcholine is deficient in the Alzheimer's brain and these deficiencies have been associated with Alzheimer's-related impairments, it has been thought that finding ways to increase this chemical messenger might hold promise in treating the disease.
Additionally, lecithin and choline, which increase the availability of acetylcholine, have received some research attention. Drugs such as physostigmine and THA (tetrahydroacridine) which make acetylcholine available longer in the brain by blocking its destruction, have seemed promising in developing